Pollen spectrum variations in the atmosphere of Cagliari, Italy

We report on airborne pollen sampling in theatmosphere of Cagliari (southern Sardinia) inthe two-year period 1999–2000, with the aim ofsupplementing and extending the knowledge ofthe city air plankton. The total pollen grainswas 23,087. They belong systemically to 52families, including 32 trees and/or shrubs and20 herbaceous essences.The families with the highest airborne pollenincidence were the Cupressaceae, Pinaceae,Urticaceae, Anacardiaceae, Oleaceae, and thePolygonaceae.Compared to a previous monitoring, morefamilies and fewer airborne pollen grains wereobserved in this study. In addition, one airpollen component was observed that had neverbeen monitored in previous samplings. Oncomparing our data with national mean figures,the major anthesis is brought forward by amonth as a result of the particularmeteorological conditions that characterise theSardinian climate.The studies carried out disclosed therelationship between air pollen concentrationand meteorological factors. We also compiled apollen calendar showing data on monthly pollenconcentrations, from which a great deal ofuseful and important information has beenobtained.     

Imposex expression in Hexaplex trunculus from the North Tunis Lake transplanted to Bizerta channel (Tunisia)

Adult specimens of the muricid gastropod Hexaplex trunculus were collected from their natural habitat: the Lake Club station located in the North Tunis Lake, a sampling site characterized by the absence of shipping activity and an imposex incidence of 12.9%. These specimens were transplanted to a sampling site with intense shipping traffic: the Bizerta channel, where a preliminary survey detected an imposex incidence of 100%. The transplanted specimens were tagged prior to release and periodical recaptures were made every 60 days during a study period of 8 months (from July 2004 to March 2005) in order to compare the imposex development between both sampling sites. After 5 months of exposure in the Bizerta channel, all transplanted females were affected by imposex (with the development of an incomplete male genital tract). Microscopic examinations showed that imposex begun by the development of a small portion of vas deferens located halfway between the expected position of the future penis and the vagina. The imposex indices used in this study were the imposex frequency (I (%)), the vas deferens sequence index (VDSI), the relative penis length index (RPL), the average female penis length index (FPL) and the average female vas deferens length (VDL). All these indices increased in the transplanted population as compared to the population from the original sampling site, but VDSI and VDL were considered the best indices to assess the environmental pollution by tributyltin (TBT) and its deleterious effects in H. trunculus.     

Unusual record of bluemouth rockfish <Emphasis Type="Italic">Helicolenus dactylopterus</Emphasis> (Osteichthyes: Scorpaenidae) in Tunis Southern Lagoon (Northern Tunisia,Central Mediterranean)

The record of bluemouth rockfish Helicolenus dactylopterus (Delaroche, 1809) at low depth suggests that the species is prone to large vertical migrations. This capture confirms the occurrence of the species in the Tunisian waters where it is known as very rare. It confirms also the success of ecological restoration of Tunis Southern Lagoon and the possible establishment of fish populations, mainly due to a favourable biological environment, mostly constituted by crustacean species among them, species belonging to the genus Sphaeroma Latreille, 1802 play an important role.     

Pollen deposition in country villages of Eastern Liguria (Northern Italy)

Summary Recent pollen rain in 14 country villages of Ligurian hinterland was examined, in the framework of pollen deposition studies based upon moss polsters analysis, now in progress. The above mentioned localities are prevailingly situated in the Trebbia, Aveto and Vara valleys, within 300 and 1000 m a.s.l. For each locality a moss sample was examined (two for Torriglia: north and south) consisting of several sub-samples from various zones of the built-up area. All the samples have proved rich in pollen and provided spectra in accordance with qualitative and quantitative features of the urbanized areas vegetation and the spontaneous one of the neighbourhood. Sticking to general considerations, an attempt was made to compare the present results with those of the city area of Genova, previously obtained with the same methods.     

Distribution of hydrocarbon residues in the sediment from Bizerte lagoon (Northern Tunisia)

The study of hydrocarbon residue by infrared spectrophotometry in the deposits of the Bizerta Lagoon allows us to recognize a polluted zone sector of the Menzel Bourguiba Arsenal. The Eastern part of the lagoon, a zone of "oyster parks" is not affected by pollution. Its average contents of hydrocarbon residues are clearly below the maximum content determined by international regulations. The distribution of hydrocarbon residues in the superficial sediments following three well differentiated zones, reflects the weak hydrodynamism in the lagoon. The vertical variations of this pollution agent contents show the preferential accumulation of the terrigenous material, from lake Ichkeul , in the western part and the weak rate of sedimentation in the eastern zone.     

Genotypic and Phenotypic Profiles of Enterotoxigenic <Emphasis Type="Italic">Escherichia coli</Emphasis> Associated with Acute Diarrhea in Tunis,Tunisia

No past studies of acute diarrhea in Tunisia have examined the phenotypic and genotypic profiles of enterotoxigenic Escherichia coli (ETEC) isolates. We determined 65 ETEC isolates derived from a total of 327 E. coli isolates collected from a previous study (acute diarrheal and healthy persons, children and adults n = 214) and 32 E. coli isolates derived from an acute diarrheal outbreak in Kabaria-Ennour city, Tunis. All E. coli isolates were screened by polymerase chain reaction (PCR) for ETEC virulence genes: sta (heat-stable toxin gene) and elt (heat-labile toxin gene). Seventy-two percent (47 of 65) of ETEC strains expressed the sta gene only, 21.5% (14 of 65) expressed the elt gene and 6.1% (4 of 65) expressed both genes. For the outbreak isolates, the elt gene was predominant (10 isolates out of 14). Ganylioside GM1 enzyme-linked immunosorbent assay (GM1-ELISA) was used to validate the PCR results and this was confirmed by dot blot assay. The same results were obtained. The most common colonization factors (CFs) were CFA/I (44.6%) and coli surface antigen 6 (CS6) (11%), and 44.6% of the isolates showed no association with either CFAs. Resistance of ETEC isolates to tetracycline (38.5%), streptomycin (26%), and beta-lactam agents (ticarcillin 26%, amoxicillin 24.6%, cephalotin 21.5%) was common. Regarding serotypes, the majority of ETEC isolates serotyped as O86:H(-) (n = 16), O128:H2 (n = 11), and O127:H21 (n = 10). Other serotypes found were O111:H(-) (n = 6) and O126: H(-) (n = 5). DNA macrorestriction fragment analysis by pulsed-field gel electrophoresis (PFGE) using the XbaI enzyme was conducted to investigate the epidemiological clonal relationship among ETEC isolates. Major patterns were identified among which some of outbreak ETEC isolates belonged. These data suggest that a proportion of acute diarrhea in Tunis represents the confluence of small epidemics by clonality-related ETEC isolates that are transiently introduced or that persist in our community.     

Co-Circulation of Toscana Virus and Punique Virus in Northern Tunisia: A Microneutralisation-Based Seroprevalence Study

Background

In northern Tunisia, the co-circulation of two related sand fly-borne phleboviruses, Toscana virus (TOSV) and Punique virus (PUNV) was previously demonstrated. In contrast to TOSV, a prominent human pathogen, there is no data supporting that PUNV is capable to infect and cause disease to humans. We studied the respective involvement of TOSV and PUNV in human infections in northern Tunisia through a seroprevalence study.

Methods

The presence of TOSV and PUNV neutralising antibodies (NT-Ab) was tested in human sera collected from 5 districts of the governorate of Bizerte, and the titres of NT-Ab were estimated by microneutralisation (MN) assay.

Principal Findings

A total of 1,273 sera were processed. TOSV and PUNV NT-Ab were detected in 522 (41%) and 111 sera (8.72%) respectively. TOSV seroprevalence varied from 17.2% to 59.4% depending on the district. Analysis of TOSV geometric mean titre values demonstrated a constant increase according to the age. The vast majority of sera containing NT-Ab were found to be more reactive toward TOSV than PUNV. Indeed, past infections with PUNV and TOSV were undisputable for 5 and 414 sera, respectively.

Conclusions

PUNV may be capable to infect humans but at a low rate. TOSV is responsible for the vast majority of human infections by sand fly-borne phleboviruses in northern Tunisia. TOSV must be considered by physician and tested in diagnostic laboratories for patients with meningitis and unexplained fever in northern Tunisia.     

Mutation spectrum of primary hyperoxaluria type 1 in Tunisia: Implication for diagnosis in North Africa

Background

Primary hyperoxaluria type 1 (PH1) is an autosomal recessive inherited metabolic disease, characterized by progressive kidney failure due to renal deposition of calcium oxalate. Mutations in the AGXT gene, encoding the liver-specific enzyme alanine glyoxylate aminotransferase, are responsible for the disease. We aimed to determine the mutational spectrum causing PH1 and to provide an accurate tool for diagnosis as well as for prenatal diagnosis in the affected families.

Methods

Direct sequencing was used to detect mutations in the AGXT gene in DNA samples from 13 patients belonging to 12 Tunisian families.

Results

Molecular analysis revealed five mutations causing PH1 in Tunisia. The mutations were identified along exons 1, 2, 4, 5 and 7. The most predominant mutations were the Maghrebian “p.I244T” and the Arabic “p.G190R”. Furthermore, three other mutations characteristic of different ethnic groups were found in our study population. These results confirm the mutational heterogeneity related to PH1 in Tunisian population. All the mutations are in a homozygous state, reflecting the high impact of endogamy in our population.

Conclusion

Mutation analysis through DNA sequencing can provide a useful first line investigation for PH1. This identification could provide an accurate tool for prenatal diagnosis, genetic counseling and screen for potential presymptomatic individuals.     

Grapevine viruses in Tunisia

Tunisian grapevine culture is affected by many viruses caused by some phytovirus belonging to nepovirus, closterovirus and trichovirus groups. The present work deal with the economically important viroses identified in tunisian grapevines. We present here the development methods to detect these viruses in propagating material. The important viruses biologically, biochemically, serologically and using molecular techniques, characterised are: GFLV, GLRaV3 and GVB. The genetic polymorphism analysis was also carried and tunisian isolates were compared to previously described ones in literature.     

Restoration and Rehabilitation of Degraded Ecosystems in Arid and Semi-Arid Lands. II. Case Studies in Southern Tunisia, Central Chile and Northern Cameroon

A model of ecosystem degradation and three possible responses to it—restoration, rehabilitation, and real-location—is applied to ongoing projects in the arid mediterranean region of southern Tunisia, the subhumid mediterranean region of central Chile, and the semiarid tropical savannas of northern Cameroon. We compare both nonhuman and human determinants of ecosystem degradation processes in these contrasted regions, as well as interventions being tested in each. A number of quantifiable “vital ecosystem attributes” are used to evaluate the effects of ecosystem degradation and the experimental responses of rehabilitation on vegetation, soils and plant-soil-water relations. We argue that attempts to rehabilitate former ecosystem structure and functioning, both above- and below ground, are the best way to conserve biodiversity and insure sustainable long-term productivity in ecosystems subjected to continuous use by people in arid and semi-arid lands of “the South.” The success of such efforts, however, depends not only on elucidating the predisturbance (or slightly disturbed) structure and function of the consciously selected “ecosystem of reference,” but also on understanding and working with the socioeconomic, technical, cultural, and historical factors that caused the degradation in the first place.     

The Tauber Pollen Trap,a Discussion of Its Usefulness in Pollen Deposition Studies

In connection with pollen deposition studies some discrepancies between Tauber traps and open collectors were discovered. Field observations showed that the aerodynamic lid of the Tauber trap itself acted as a pollen trap by redeposition e.g. because of rainsplash. In an experiment coal dust in the size range of pollen was introduced in a turbulent air stream passing over the trap. Great quantities of coaldust were captured on the aerodynamic lid. By exposure to artificial rain it was observed that the splashing effect of raindrops brought coal dust into the sampler. By application of Corylus pollen on the aerodynamic lid and exposure to rain, it was found that great amount of pollen is transferred by raindrop splash to the trap. This contamination of the pollen contents of the trap is so serious that the usefulness of the Tauber trap for quantitative evaluation of the pollen deposition is doubted unless the trap is protected in some way. Further tests of this effect have been planned.     

Surveillance system of maternal mortality in the Tunis region

In the framework of a national strategy of reduction of the maternal mortality rate. Tunisia has set up a follow up system of maternal deaths occurring in public facilities to analyse their causes, the levels of deficiency and to propose solutions for preventing them. This note aims at describing the system, its results, its efficiency and its limitations in the Tunis region for the years 1999 and 2000. The results show a maternal mortality rate estimated at 80 for 100,000 births in public facilities of the region: the main causes being haemorrhage (42.1%) followed by infection (13.2%). The proportion of avoidable deaths is 87%:74% possibly avoidable and 13% certainly avoidable, factors related to women behaviour have also contributed to 45% of cases. The system flows are however intricated, and related to organization: an underestimation of risk by the patient (33%), an inadequate watch during the postpartum period (25%), a late hospitalisation (22%) and not enough reanimation equipment. Nevertheless, this control system has achieved part of its objective by starting up a quality approach to obstetrical cares and by warning health professionals such as obstetricians, anaesthetists, blood banks in charge, hospital managers and other medical teams. The limitations of the system are tied to the follow up of the real implementation of recommendations stated in reports at a local as well as central levels.     

拟南芥花粉活力的测定及其在花粉发育研究中的应用

花粉发育是植物生活周期中一个重要且复杂的过程,需要多种基因的参与。花粉发育是否完善可以根据花粉形态特征,并通过检测花粉的生活力、萌发力、可育性和受精能力等生理特征来判断。以拟南芥候选基因突变体为材料,通过对花粉的这些生理特征的检测,可以初步推测候选基因参与花粉发育的功能和作用机制。本文介绍了用于花粉活力测定的几种技术的原理和方法,以及应用这些方法进行花粉发育研究的进展。     

Pollen calendar of Nagpur,India

Daily observations on aerial pollen at Nagpur, India, for one year, at the heights of 1 m, 15 m and 40 m, showed that their number decreased with increase in height. One third of the pollen came from grasses, followed by trees (29.3%) and weeds (26.0%). In all 26 pollen types were identified. Anemophilous plants contributed 61.5% to the total pollen catch, whereas the contributions of entomophilous and amphiphilous plants were only 14.2% and 13.0%, respectively. There were two principal seasons of aerial pollen: August to November, dominated by weed-grass pollen; and January to May, dominated by tree-grass pollen. Grasses, Amaranthaceae—Chenopodiaceae, Ailanthus Papilionaceae—Caesalpiniaceae and Dodonaea were the first five most abundant types of pollen in Nagpur atmosphere. Grass pollen dominated in the air throughout the year, except during January when Dodonaea pollen outnumbered them.     

Pollen, Mating and Paternity in Agamospermous Angiosperms

Abstract This review article deals with the male function in agamospermous plants, which is still not fully recognized. Of particular interest are mating and paternity problems. Pollen of agamospermous donors may influence female fitness in early mating phases by contributing the recognition substances or inducing spontaneous seed development. Various interactions between the sperm cell(s) and the female gametophyte at later phases may include (1) occasional double fertilization, (2) occasional syngamy, (3) pseudogamy, and (4) hemigamy. In the first two processes the offspring are sired normally. In pseudogamy, the offspring is maternal, the male contribution being restricted to endosperm paternity. In hemigamy, male function may include induction of the egg cell development only (maternal offspring), or the induction of the egg cell development as well as independent participation of the sperm cell in the offspring development leading to the formation of chimeras. It is concluded that the sperm may be a limiting resource in at least some agamospermous plants. Possible directions of future research are briefly outlined.